Often, users interact with an application up to a certain point, and thereafter restart the application. In web applications run in an internet browser, it is exceedingly easy to restart the application by running the browser's standard refresh command, or navigating to a different web site and back. Sometimes, some or all of the state of the application is not preserved prior to a restart. In computer applications that show significant user interface at the same time (such as multiple windows/pages, multiple user interface controls, and so forth), this could represent significant loss of state.
To preserve state, some applications allow the user to save in response to an explicit save command (e.g., by pressing the save button). Other applications allow the user to designate time intervals for automatic saving of the state. In either case, however, there is often some state that is not preserved through the restart. Some applications automatically save application state when the application is shut down, but not all shutdowns are orderly, and thus sometimes save at shutdown does not happen. Even if saves happen, the saves often occur in a local save only, and thus the restart cannot be from a different machine without losing state. Furthermore, if there is a loss in local storage performance, the locally saved state may not be useful anyway.